These are HP Z3100 printers, identical in absolutely every way except carriage length. Same inks, same paper, same image, same size, same profile, same options set, etc., etc. The inks are the same, all genuine HP #70 Vivera. All inks and printheads are in warranty. I would never use off-brand inks to save a couple of dollars.

I opted to omit the make/model in my original post, as I felt that info would only muddy the discussion.

Believe me, they are not the same.

I could have two of the exact model Canon, Epson or HP and they will produce slightly different results.

I would profile both of them as one of your heads is definitely printing slightly different than the other.